OBD2 real-time Coolant temperature alert (DIY or BUY)

hgg

Dedicated Member
Joined
Jan 30, 2019
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29
Model of Z
Z3
Hi,

An unnoticed over temperature situation can cause huge damage to your car and
all you get is a little red warning light when its too late, and in the case of the Z3
its also very easy to miss it with the top off.

It is extremely easy for the car manufacturers to incorporate a loud buzzer that will save the situation
in time but for some reason they are not doing it. They have sound warnings for other things like
turn signals or seat-belts but for the thing that can cause great damage to you car, sorry its too much...

So I am planning to start an Arduino project that will read real time data from the OBD2 port
situated under the steering wheel and display it on a small LCD with a very loud over temperature
buzzer. But before starting this project I would like to ask if anyone knows of an already made
solution. I have bought recently the following OBD2 display but it does not work with the
2001 Z3. It works fine on cars with KWP2000.



My OBD2 scanner which reads real time data no problem, identifies the Z3 protocol as ISO 9141-2

There is another Chinese OBD2 display that lists this protocol as supported but the seller says
that it is not compatible with the Z3 based only on the production year. I will give that a try
as well.



So, if anyone knows of a solution that works with the 2001 Z3, please share.
(I am not interested in solutions with custom temp sensors, only from OBD2)

Thank you.
 
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Zephyr

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Hi,

I have bought recently the following OBD2 display but it does not work with the
2001 Z3. It works fine on cars with KWP2000.

have you tried connecting the pins on the round obd in the engine bay and then read from the interior one?
this trick gave full access to my obd reader from inside the car.
IMG_4513.jpeg
 

hgg

Dedicated Member
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Jan 30, 2019
Points
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Model of Z
Z3
I have heard of this mod but I haven't tried it.
Have you tried it with an OBD2 display?
 

Zephyr

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I tried it with my scanner (showed 45 options after this instead of 7 prior to that) a carly bluetooth adapter that sends data to the phone (worked 100% of potential) and a cheapo obd display that locks to one reading each time (i wanted to constantly check my maf readings) and it worked. why not give it a try? Just connect these two pins with a wire, no harm done.
 
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hgg

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Jan 30, 2019
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Model of Z
Z3
I will give it a try.
Maybe that is why these Chinese readers cannot fully open the ISO9141-2 protocol.
 

hgg

Dedicated Member
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Jan 30, 2019
Points
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Model of Z
Z3
I just did the mod but the OBD2 display still cannot recognize the protocol.
So the question remains.

If somebody knows an OBD2 display that works with the 2001 Z3 please share.
Thanks.
 

hgg

Dedicated Member
Joined
Jan 30, 2019
Points
29
Model of Z
Z3
Good news, at least for me..

For anyone interested, the second OBD2 display shown at the top of the thread
works perfectly fine with a 1.9 2001 Z3 despite the seller saying that it will
not work! It identifies the ISO 9141-2 protocol and displays the engine
temperature correctly. The alarm works and is very audible which was
the whole point. (I've just received the unit) I have left the engine OBD
port wire modification that Zephyr suggested as is.

The interface is easy and functional.
The only negative is that it is a bit bulky with no reason, but I will design
a 3D printed case to minimize its footprint.

At last a coolant temperature alarm that works! :thumbsup:
 

Ianmc

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British Zeds
The M44 Massive
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Oct 12, 2014
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New Forest
Model of Z
Z3 (M44)
Z3s have a water temperature gauge; can't see the need for an alarm!
 

hgg

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Jan 30, 2019
Points
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Model of Z
Z3
The window in which you can save your car from overheating damage is measured in seconds...
You can very easily miss the red light warning especially if you are driving in the sun with the
top open. With an audible alarm you can immediately stop your car and avoid any damage.
 

Duncodin

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Pontrhydyrun
Model of Z
Z3 M44
Z3s have a water temperature gauge; can't see the need for an alarm!
I was thinking the same. There's a gauge right there.

Maybe you need to be of an age. I grew up looking at gauges continuously because if we took our eyes off the gauges just for a moment something would go off the scale.

But now I have an idea to put a 7" tablet on my dash showing more info than I could ever need. Just for the heck of it.

Although no audio. I don't like sudden beeps. My MB beeps at me sometimes if it thinks I'm driving too close to something ahead such as a dustbin on the path in the bend I'm going round and the beep makes me jump out of my skin.
 

hgg

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Model of Z
Z3
I was thinking the same. There's a gauge right there.

Maybe you need to be of an age. I grew up looking at gauges continuously because if we took our eyes off the gauges just for a moment something would go off the scale.

But now I have an idea to put a 7" tablet on my dash showing more info than I could ever need. Just for the heck of it.

Although no audio. I don't like sudden beeps. My MB beeps at me sometimes if it thinks I'm driving too close to something ahead such as a dustbin on the path in the bend I'm going round and the beep makes me jump out of my skin.
Your eyes should be on the road... You can see that they are using so many audible alerts
for less important things. Sounds for turning signals, continuous beeping for minutes (!)
if you do not wear your seat belt when a flashing indicator would be more than enough,
but when it comes to burning your engine, the manufacturers think that a small light
is all you need. :)
 

TriumphZ3

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Maybe you need to be of an age. I grew up looking at gauges continuously because if we took our eyes off the gauges just for a moment something would go off the scale.
I grew up in an age where speedometer and fuel were the only gauges. If the engine was overheating, steam came from under the bonnet. They don't call additional gauges 'worry gauges' for nothing, you do tend to study them when driving...
 

the Nefyn cat

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Actually in Nefyn. My, that took a while.
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2.2i Sport
I was taught to look at the gauges, too. There's no need to stare at them, and it should be fairly obvious out of the corner of your eye if anything is going wrong. Goes with checking the mirrors (yes, all of them) as you drive along. Although it does seem that plenty of people don't bother with that sort of stuff, anyone else had some tw@ stop in front of them and immediately start reversing? Lucky I was taught not to get too close in the first place. "Assume the rest of them are idiots" said my instructor, and I feel that was good advice.
 

t-tony

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E89 Z4 23i Auto
Yep, I was given that self same advice by my intructor too mate. And it still holds true to this day, in fact maybe even more so.

Tony.
 

Nodzed

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I was taught to look at the gauges, too. There's no need to stare at them, and it should be fairly obvious out of the corner of your eye if anything is going wrong. Goes with checking the mirrors (yes, all of them) as you drive along. Although it does seem that plenty of people don't bother with that sort of stuff, anyone else had some tw@ stop in front of them and immediately start reversing? Lucky I was taught not to get too close in the first place. "Assume the rest of them are idiots" said my instructor, and I feel that was good advice.
Yep, ask @mwpe, some Tw@t stopped in front of him in Scotland and started reversing. :whistle::whistle::whistle:
 

TriumphZ3

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My old art teacher many moons ago was a bit of a joker, and he once started a whole debate about breathing, which is natural until you start to think about it. Are you breathing deeply enough? How regularly? Once your brain tries to take over it becomes a nightmare. Same thing with gauges. Does the needle normally sit at that point? Have they moved even slightly? Has one needle dropped and should I be worried, or will it return to the usual position again? If it did, why? It's easy to become paranoid.
When I was a child my father drove an old Hillman Minx, and every time we had to go somewhere, eg 70 miles to the seaside, he'd not be happy with the car and would have to get someone to look at it, so we left home very late, or else had to rush home in case it broke down. This was usually because the red ignition jewel had momentarily flickered, or the green oil pressure light had come on and gone off again instantly. He could never relax and enjoy the trip.
 
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